Method and device for the supply of electrical loads in or on a pneumatic device with electrical power energy

ABSTRACT

A method and a device for the supply of electrical loads in or on a pneumatic device with electrical power energy. The pneumatic device is connected by way of a pneumatic line with a source of pressure. The transmission of power energy to the pneumatic device takes place using acoustic waves, microwaves, changes in pressure or a flow of gas in the pneumatic line. Conversion of such transmitted energy into the electrical supply energy occurs in or on the pneumatic device. This means that electrical lines for electrical power supply may be dispensed with and that the transmission of energy takes place only by way of the pneumatic line.

This application is a national stage application of InternationalApplication Number PCT/EP00/08433 filed on Aug. 30, 2000 which claimspriority to German Application No. 19942509.4 filed on Sep. 7, 1999.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method and a device for the supply ofelectrical loads in or on a pneumatic device with electrical powerenergy, the pneumatic device being connected by way of a pneumatic linewith a source of pressure.

2. Description of the Prior Art

For the control of pneumatic equipment, such as valve arrangements,cylinders, drives and the like, there is on the one hand the requirementfor the supply of compressed air by way of a pneumatic line and on theother hand for electrical supply lines for the supply of electricalpower energy and of electrical control signals and furthermore possiblyreturn lines for the return of sensor signals. If a plurality of controldevices, such as valves, are arranged on one pneumatic device, togetherwith a plurality of sensors, there is a corresponding increase in thenumber of electrical lines, safety which frequently means that there isa somewhat chaotic arrangement of lines involving high costs for theinstallation, servicing and repair of such equipment.

The German patent publication 19,526,459 discloses the operation of abus station valve station comprising a plurality of valves by way of abus line, by way of which it is also possible for sensor return signalsto be passed, but there is here a requirement for additional electricalpower lines and the pneumatic line so that in this case the complexityof installation is substantial.

Although the German patent publication 3,147,399 A1, the German patentpublication 3,209,189 A1 and the German patent publication 4,126,403 C2disclose the transmission of control or sensor data ultrasonicallythrough metallic tube supply network, the power energy is not sotransmitted and furthermore such method is not applicable to pneumaticlines, which conventionally consist of plastic material

OBJECT AND SUMMARY OF THE INVENTION

Accordingly one object of the present invention is to provide a methodand a device by means of which the number of connecting lines leading toa pneumatic device to be controlled may be substantially reduced andinstallation may be simplified.

The advantage of the device in accordance with the invention is moreparticularly that using the pneumatic line, which is present in any caseit is simultaneously possible for power energy to be transmitted forelectrical loads in the pneumatic device so that the no separate linesare required for this purpose. In this case transmission is by way ofthe gaseous medium or, respectively, conduction is by means of acousticwaves, microwaves, changes in pressure or by means of flow energy of thegaseous medium subject to pressure. For this reason the transmission ofenergy is possible in the case of conventionally employed plastic lines.The conversion into electrical power energy is performed directly on orin the pneumatic device.

In accordance with a further preferred development the pressure of thegaseous medium in the pneumatic line is utilized for driving amicroturbine with an electrical generator, that is to say the flowenergy of the gaseous medium under pressure is directly converted in orat the pneumatic device into electrical power energy.

In an alternative design of the invention the acoustic waves or changesin pressure are converted by means of the piezo effect or by capacitiveor inductive conversion methods at least partially into electrical powerenergy in the pneumatic device. For the conversion of the acoustic wavesor changes in pressure use is preferably here made of a piezoelectric,capacitive or inductive converter or an oscillating piston arrangement.Such a converter or an oscillating piston arrangement is also preferablyprovided in a control and/or data receiving means, connected by way ofthe pneumatic line with the pneumatic conversion of the electricalenergy into acoustic waves to be supplied to the pneumatic line or intopressure changes.

It is a advantage for the transmission of control and/or sensor signalsbetween the electronic control and/or data receiving means and thepneumatic device to be by way of the pneumatic line using acousticsignals, microwaves or changes in pressure. For this purpose preferablydifferent frequencies and/or signal sequences and/or modulation and/orpressure pulse sequences are provided, the transmission taking placepreferably bidirectionally in order to be able to return sensor signalsas well.

For the transmission of such control and sensor signals the controland/or data receiving means and the pneumatic device are preferablyprovided with at least one first converter for the conversion ofelectrical signals into acoustic signals or pressure changes and with atleast one second converter for the conversion of the acoustic signals orpressure changes into electrical signals. For the bidirectional datatransmission both the control and/or data receiving means and also thepneumatic device is provided with a first converter and with a secondconverter, one first converter and one second converter being designedin the form of a combined bidirectional converter if desired. For thispurpose it is possible to employ more particularly piezoelectric orhowever also inductive or capacitive converters.

The converters for the supply of power energy may be advantageouslyidentical to the converters for the conversion between acoustic signalsor pressure changes and electrical control and/or sensor signals, sincewith the performance of this double function better utilization ispossible.

In an alternative design the transmission of control and/or sensorsignals between the electronic control and/or data receiving means andthe pneumatic device may also takes place in a wireless manner and moreparticularly by radio or infrared signals or by way of optical guidearranged in or on the pneumatic line or integrated in same in the lattercase the control and/or data receiving means and the at least onepneumatic device will preferably be provided respectively with anoptical transmitter and/or a optical receiver.

In order to make the supply voltage available continuously, for instancein the case of an energy requirement which is increased for a shorttime, it is advantageously possible to provide a storage means and moreparticularly a capacitor or a storage cell, for the storage of theelectrical power energy produced in or at the pneumatic device.

A converter which is more especially in the form of a microcomputer inor on the pneumatic device preferably serves for the conversion of thetransmitted signals into control signals for at least one control means,as for example a valve, in the pneumatic device and/or for conversion ofsensor signals into signals to be transmitted.

The control and/or data receiving means is preferably designed in theform of a bus station connected with a data bus. In this respect aplurality of pneumatic devices may be connected with this bus station byway of pneumatic lines directly or by way of branch lines.

In the case of systems of large size it is possible furthermore forseveral bus stations to be connected with the data bus, which arerespectively connected with at least one pneumatic device.

The at least one converter and the means for making the electrical powerenergy available are preferably integrated in the pneumatic device sothat the arrangements are compact, which for complete installation onlyhave to be connected by way of a single pneumatic line.

Working examples of the invention are illustrated in the drawings andwill be explained in the following description in detail

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block circuit diagram of a device for the transmission ofdata between a bus station and a pneumatic cylinder.

FIG. 2 shows a similar arrangement to that of FIG. 1 in a detailed viewwith a microturbine for producing electrical power energy in thepneumatic cylinder.

FIG. 3 is a diagrammatic view to show the operation of three pneumaticcylinders by way of three bus stations.

FIG. 4 shows a similar arrangement, in the case of which three pneumaticcylinders are connected with a bus station.

FIG. 5 shows a similar view to that of FIG. 1, in which one connectionof a bus station is connected with a bus station by way of

FIG. 6 shows a block circuit diagram of a device for the transmission ofdata between a bus station and a pneumatic cylinder using wirelesstransmitters.

FIG. 7 is a block circuit diagram of a device for the transmission ofdata between a bus station and a pneumatic cylinder using opticaltransmitters.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the case of the working example of the invention illustrated in FIG.1 one pneumatic cylinder 10 is controlled by way of an electrical databus 11, as for example a field bus. A pneumatic pressure source 12 isconnected by way of a pneumatic line 13, consisting for instance offlexible plastic, with the pneumatic cylinder 10. In terminal region ofthe pneumatic cylinder 20 housing 14 two valves 15 and 16 arerespectively integrated, which for instance are in the form of 3/2 wayvalves. As an alternative to this it would be possible to have a 4/3 wayvalve. The two valves 15 and 16 are respectively on one side connectedwith the pneumatic line 13 and a venting duct 17 and on the other sidewith one of two cylinder chambers 18 and 19 on either side of a movingpiston 20.

Electrical control signals of the valves 15 and 16 are supplied by wayof the data bus 11 of an electronic control and data receiving means 21.The latter comprises a bus station 22 connected with the data bus 11,such station 22 being connected by way of a bidirectional converter 23with the pneumatic line 13. The bidirectional converter 23 is forexample designed in the form of a piezoelectric converter and convertsthe supplied electrical signals into the corresponding acoustic signalsor sonic oscillations, which are propagated in the gaseous medium in theline 13 and finally reach a corresponding bidirectional converter 24 inthe pneumatic cylinder 10, where they are again converted intocorresponding signals. The transmission of the data comprised in theelectrical signals takes place either by way of different frequencies,which may extend as far as ultrasonic frequencies and be modulated aswell, or by way of acoustic signal sequences or, respectively,corresponding changes in pressure or pressure surges in the gaseousmedium. As an alternative it is possible for the transmission to alsofor example take place using microwaves, which are also propagated inthe gaseous medium, suitable microwave converters then being necessary.

The electrical signal produced by the bidirectional converter 24 aresupplied in the housing 14 to a microcomputer 25, where they are decodedand, dependent of the result of decoding, are converted into controlsignals for the two valves 15 and 16.

For supplying the microcomputer 25 with power and (directly orindirectly) the valves 15 and 16 a fraction of the electrical signalsproduced in the converter 24 is rectified in a rectifier arrangement 26and supplied to a storage means 27, which for example is in the form ofa capacitor. The storage means 27 provides a constant supply of currenteven when actually no signals are arriving by way of the line 13 orthere is a current surge or increased energy requirement. In a simplerdesign it is possible to dispense with a storage means 27.

Having regard the relatively low level of electrical energy availablethe valves 15 and 16 are for example in the form of valve arrangementswith a multiple pilot function, more particularly with the use ofpiezoelectric valves.

Customarily sensors are arranged on such pneumatic cylinders 10 or onother pneumatic devices, the sensor signals having to be returned or fedback to the control. In the working example a pressure sensor 28 and aposition sensor 29 are illustrated to detect the position of the piston.The same are connected with the inputs of the microcomputer 25, wherethe corresponding sensor signals are digitalized and encoded and in thisform supplied to the bidirectional converter 24. Here they are convertedin the corresponding acoustic, sonic or pressure signals, and suppliedby way of the line 23 to the converter 23, where they are converted backinto electrical signals and then supplied to the bus station 22. Thecorresponding information is digitalized there and supplied by way ofthe data bus 11 to a master station, not illustrated, which for examplemay be a PC.

It is of course possible as well, in the case of decentralizedintelligence, to further process the sensor signals partly in themicrocomputer 25 and/or in the bus station 22 completely or partially orto take them into account for control.

Instead of the microcomputer 25 another decoding and encoding means mayof course be used.

The converter 24, the microcomputer 25, the rectifier arrangement 26 andthe storage means 27 in the housing 14 of the pneumatic cylinder 10 arecollected together in a control and data transmission means 30, whichfor example may be inserted bodily or may be adapted to be externallymounted.

Data transmission by way of the line 13 in the two opposite directionsmay for example be within set time windows or slots or in accordancewith the master/slave principle. Furthermore the production of the powerenergy may for example take place in alternation with data transmissionin time windows, or however the storage of energy may occur in thestorage means 27 respectively in periods, in which there is notransmission of data such transmission being controlled by themicrocomputer 25. As an alternative to this it is also possible for afraction of the electrical signals to be constantly utilized for powersupply.

An alternative design of a control and data transmission means 31 isillustrated in FIG. 2, which may be employed instead of the control anddata transmission means 30. Identical or functionally equivalentcomponents or assemblies are given the same reference numerals and notdescribed over again. The power energy is here not derived from thetransmitted acoustic signal or changes in pressure in the gaseousmedium, and instead the pressure in the gaseous medium is employed fordriving a microturbine 32 with a microgenerator mounted thereon orintegrated in it. Since the line 13 is constantly under pressure, suchpower energy may be produced at all times so that no storage means isrequired, though it however may naturally be provided. The electricalenergy produced by the microturbine 32 is processed in a powerprocessing circuit 32 and supplies the microcomputer 25 and furthermorethe driver stage 34 connected with the output thereof for operation ofthe valves 15 and 16. Such a driver stage 34 can of course also beprovided in the case of the control and data transmission means 30.

Instead of the microturbine 32 it is possible to provide a differentmicromechanical system for the production of electrical energy, as forexample an oscillating piston arrangement.

The system illustrated in FIG. 3 serves for the operation of threepneumatic cylinders 10, 40 and 70. The control and data receiving means21 and the pneumatic cylinder 10 with its control and data transmissionmeans 30 and its valves 15 and 16 are the same as in the arrangement ofFIG. 1 (or FIG. 2). Two further control and data receiving means 51 and81 are correspondingly connected with the data bus 11, which is drivenusing a master station 35 designed in the form of a PC, such receivingmeans 51 and 81 being connected by way of the lines 43 and 73, whichhave corresponding control and data transmission means 60 and 90, withthe pneumatic cylinders 40 and 70. The pneumatic cylinders 40 and 70have valves 45 and 46 and, respectively, 75 and 75, corresponding to thevalves 15 and 16. It is in this manner that the overall arrangement maybe expanded to any desired extent.

As an alternative to this it is also possible, as illustrated in FIG. 4,to control all pneumatic cylinders 10, 40 and 70 using a control anddata receiving means 21, with which for this purpose the three pneumaticlines 13, 43 and 73 are connected. In this case in accordance with FIG.4 further control and data receiving means may be connected with theelectrical bus 11, and again control a plurality of pneumatic cylindersor other pneumatic device and/or receive the sensor signals therefrom.FIG. 5 shows a possible modification of the system in FIG. 4, becausehere only the pneumatic line 43 is connected with the control and datareceiving means 21, whereas the pneumatic lines 13 and 73 are connectedby way of branches or T-junctions with this line 43.

The pneumatic cylinders 10, 40 and 70 employed in the working examplesare only given as examples. Instead of these pneumatic cylinders or inaddition thereto it is possible to employ other pneumatic devices also,such as a valve islands, pneumatic drives, servicing equipment, or plainsensor arrangements, in the case of which no control signals aresupplied.

Instead of the data transmission, as described, for transmission ofcontrol and/or sensor signals by way of the at least one pneumatic line13, 43 and 73 such data transmission may also take place in a wirelessmanner using wireless transmitters 123, 124 as shown in FIG. 6. Thewireless transmitters can be configured to use radio or infraredsignals. Alternatively, the data transmission may also take place usingoptical transmitters 223, 224 for transmitting and receiving opticalsignals. The optical transmitters 223, 224 can be arranged in or on thepneumatic line 13, 43 and 73 or integrated in it. Correspondingtransmitters and/or receivers are here comprised in the electroniccontrol and/or data receiving means 21, 51 and 81 and in the pneumaticdevice 10, 40 and 70. FIG. 7 illustrates the optical transmitters 223,224 being arranged at the connection junctions of the pneumatic line.

What is claimed is:
 1. A method for supplying electrical power toelectrical loads associated with a pneumatic device, the pneumaticdevice being connected by way of a pneumatic line with a source ofpressure for maintaining a gaseous medium under pressure and at a flowrate, said method comprising the steps of: transmitting energy to thepneumatic device through the pneumatic line by at least one of: acousticwaves; microwaves; pressure changes of the gaseous medium; and flowchanges of the gaseous medium; and converting said transmitted energyinto the electrical power.
 2. A method for supplying electrical power asdefined in claim 1, wherein a microturbine having an electricalgenerator converts the pressure of the gaseous medium into theelectrical power.
 3. A method for supplying electrical power as definedin claim 1, wherein at least one of said acoustic waves and saidpressure changes of the gaseous medium are: transmitted through thepneumatic line; and converted at least partially into the electricalpower by a piezoelectric converter.
 4. A method for supplying eletricalpower as defined in claim 1, wherein at least one of said acoustic wavesand said pressure changes of the gaseous medium are: transmitted throughthe pneumatic line; and converted at least partially into the electricalpower by at least one of capacitive converter and inductive converter.5. A method for supplying electrical power as defined in claim 1,wherein at least one of said acoustic waves, microwaves and saidpressure changes of the gaseous medium are transmitted through thepneumatic line for transmitting at least one of control signals andsensor signals between the pneumatic device and an electronic controland data receiving means.
 6. A method for supplying electrical power asdefined in claim 5, wherein said transmission of at least one of controlsignals and sensor signals are provided at a plurality of at least oneof frequencies, signal sequences, modulation, and pressure pulsesequences.
 7. A method for supplying electrical power as defined inclaim 1, wherein at least one of radio and infrared signals aretransmitted for transmitting at least one of control signals and sensorsignals between the pneumatic device and at least one of an electroniccontrol and data receiving means.
 8. A method for supplying electricalpower as defined in claim 1, wherein optical transmitters are arrangedalong the pneumatic line for transmitting optical signals of at leastone of control signals and sensor signals between the pneumatic deviceand an electronic control and data receiving means.
 9. A method forsupplying electrical power as defined in claim 8, wherein said opticaltransmitters are attached within the pneumatic line.
 10. A method forsupplying electrical power as defined in claim 8, wherein said opticaltransmitters are attached within the pneumatic line.
 11. A method forsupplying electrical power as defined in claim 1, wherein thetransmission occurs bidirectionally.
 12. A device for supplyingelectrical power to electrical loads associated with a pneumatic device,the pneumatic device being connected by way of a pneumatic line with asource of pressure for maintaining a gaseous medium under pressure andat a flow rate, said device comprising: a conversion means forconverting energy transmitted through the pneumatic line into theelectrical power, said energy being transmitted by at least one of:acoustic waves; microwaves; pressure changes of the gaseous medium; andflow changes of the gaseous medium.
 13. A device for supplyingelectrical power as defined in claim 12, wherein the conversion means isprovided in the pneumatic device.
 14. A device for supplying electricalpower as defined in claim 12, wherein the conversion means is providedon the pneumatic device.
 15. A device for supplying eletrical power asdefined in claim 12, wherein said conversion means is a piezoelectricconverter configured to convert at least one of acoustic waves andpressure changes of the gaseous medium.
 16. A device for supplyingelectrical power as defined in claim 15, further comprising: anelectronic control and data receiving means for converting electricalsignals into at least one of acoustic waves and pressure changes of thegaseous medium, said electronic control and data receiving means beingconnected to the pneumatic device through the pneumatic line andincluding at least one of: piezoelectric converter; a capacitiveconverter; inductive converter; and an oscillating piston arrangement.17. A device for supplying electrical power as defined in claim 12,wherein said conversion means is a capacitive converter configured toconvert at least one of acoustic waves and pressure changes of thegaseous medium.
 18. A device for supplying electrical power as definedin claim 17, further comprising: an electronic control and datareceiving means for converting electrical signals into at least one ofacoustic waves and pressure changes of the gaseous medium, saidelectronic control and data receiving means being connected to thepneumatic device through the pneumatic line and including at least oneof: a piezoelectric converter; a capacitive converter; inductiveconverter; and an oscillating piston arrangement.
 19. A device forsupplying electrical power as defined in claim 12, wherein saidconversion means is an inductive converter configured to convert atleast one of acoustic waves and pressure changes of the gaseous medium.20. A device for supplying electrical power as defined in claim 19,further comprising: an electronic control and data receiving means forconverting electrical signals into at least one of acoustic waves andpressure changes of the gaseous medium, said electronic control and datareceiving means being connected to the pneumatic device through thepneumatic line and including at least one of: a piezoelectric converter;a capacitive converter; inductive converter; and an oscillating pistonarrangement.
 21. A device for supplying electrical power as defined inclaim 12, wherein said conversion means is an oscillating pistonarrangement configured to convert at least one of acoustic waves andpressure charges of the gaseous medium.
 22. A device for supplyingelectrical power as defined in claim 21, further comprising: anelectronic control and data receiving means for converting electricalsignals into at last one of acoustic waves and pressure changes of thegaseous medium, said electronic control and data receiving means beingconnected to the pneumatic device through the pneumatic line andincluding at least one of: a piezoelectric converter; a capacitiveconverter; inductive converter; and an oscillating piston arrangement.23. A device for supplying electrical power as defined in claim 12,wherein said conversion means includes a microturbine having anelectrical generator for converting the pressure of the gaseous mediuminto the electrical power.
 24. A device for supplying electrical poweras defined in claim 12, further comprising a storage means for storingat least a portion of the electrical power produced by said conversionmeans.
 25. A device for supplying electrical power as defined in claim24, wherein said storage means is a capacitor.
 26. A device forsupplying electrical power as defined in claim 24, wherein said storagemeans is a storage cell arrangement.
 27. A device for supplyingelectrical power as defined in claim 12, further comprising: anelectronic control and data receiving means connected to the pneumaticdevice through the pneumatic line; at least one first converter forconverting electrical signals into at least one of: acoustic signals andpressure changes in the gaseous medium; and at least one secondconverter for converting at least one of: acoustic signals and pressurechanges into electrical signals.
 28. A device for supplying electricalpower as defined in claim 27, wherein said control and data receivingmeans is provided with said first converter and said pneumatic device isprovided with said second converter.
 29. A device for supplyingelectrical power as defined in claim 27, wherein said control and datareceiving means further comprises a second converter and said pneumaticdevice further comprises a first converter.
 30. A device for supplyingelectrical power as defined in claim 29, wherein at least said firstconverter and said second converter are combined to form a bidirectionalconverter.
 31. A device for supplying eletrical power as defined inclaim 27, wherein said first converter and said second converter are atleast one of: a piezoelectric converter; a capacitive converter; and aninductive converter.
 32. A device for supplying electrical power asdefined in claim 27, wherein said first converter and said secondconverter are identical.
 33. A device for supplying electrical power asdefined in claim 12, further comprising: an electronic control and datareceiving means for communicating with the pneumatic device; and a datatransmission means for transmitting and receiving signals between thepneumatic device and said electronic control and data receiving means,said signals being transmitted by at least one of infrared signals andradio signals.
 34. A device for supplying electrical power as defined inclaim 12, further comprising: an electronic control and data receivingmeans for communicating with the pneumatic device, said electroniccontrol and data receiving means being connected to the pneumatic devicethrough the pneumatic line; and an optical communications means fortransmitting and receiving optical signals between the pneumatic deviceand said electronic control and data receiving means.
 35. A device forsupplying electrical power as defined in claim 12, wherein the pneumaticdevice includes: at least one control means for controlling thepneumatic device; and at least one sensor for monitoring the pneumaticdevice; and said device further comprises: a microcomputer forcommunicating with both the control means and the sensor.
 36. A devicefor supplying electrical power as defined in claim 35, wherein saidconversion means and said microcomputer are integrated in the pneumaticdevice.
 37. A device for supplying electrical power as defined in claim12, further comprising: an electronic control and data receiving meansfor converting electrical signals into at least one of acoustic wavesand pressure changes of the gaseous medium, said electronic control anddata receiving means being connected to the pneumatic device through thepneumatic line and including: a bus station connected between a data busand at least one of: a piezoelectric converter; a capacitive converter;an inductive converter; and an oscillating piston arrangement.
 38. Adevice for supplying electrical power as defined in claim 37, wherein aplurality of pneumatic devices are connected by way of a plurality ofpneumatic lines with said control and data receiving means.
 39. A devicefor supplying electrical power as defined in claim 37, wherein aplurality of control and data receiving means are connected with saiddata bus, each of said plurality of control and data receiving meansbeing connected with at least one pneumatic device.
 40. A device forsupplying electrical power as defined in claim 12, wherein the pneumaticline is manufactured of flexible plastic material.